Leading roller for rising twisting machines, especially two-for-one twisting machines



Sept. 12, 1967 G. FRANZEN 3,341,100

LEADING ROLLER FOR RISING TWISTING MACHINES, ESPECIALLY TWO'FOR-ONE TWISTING MACHINES 6 Sheets-Sheet 1 Filed April 15, 1965 FIG. 4

Sept. 12, 1967 s. FRANZEN 3, I LEADING ROLLER FOR RISING TWISTING MACHINES, ESPECIALLY TWO-FQR-ONE TWISTING MACHINES Filed April 15, 1965 6 Sheets-Sheet 2 Sept. 12, 1967 G. FRANZEN 3,341,100 LEADING ROLLER FOR RISING TWISTING MACHINES, ESPECIALLY TWO-FOR-ONE TWISTING MACHINES 6 Sheets-Sheet 5 Filed April 15, 1965 Sept. 12, 1967 .F NZEN 3,341,100

LEADING ROLLER FOR R1 I G ISTING MACHINES, ESPECIALLY TWO-FORONE TWIS'IING MACHINES Filed April 15, 1965 6 Sheets-Sheet 4 3,341,100 ESPECIALLY 6 Sheets-Sheet 5 FIG. 16

Sept. 12, 1967 G. FRANZEN LEADING ROLLER FOR RISING TWISTlNG MACHINES,

TWO-FOR-ONE TWISTING MACHINES Filed April 15, 1965 NZEN 3,341,100 ISTING MACHINES ESPECIALLY STING MACHINES Sept. 12, 1967 G. F LEADING ROLLER FOR RISING TWO-FOR-ONE TWI 6 Sheets-Sheet 6 Filed April 15, 1965 United States Patent 3,341,100 LEADING ROLLER FOR RISING TWISTING MA- CHINES, ESPECIALLY TWO-FOR-ONE TWIST- ING MACHINES Gustav Franzen, Neersen, near Krefeld, Germany, as-

signor to Palitex Project-Company GmbH, Kretleld, Germany Filed Apr. 15, 1965, Ser. No. 448,307 priority, application Germany, Apr. 16, 1964,

N 24,811 21 Claims. (Cl. 226-179) The present invention relates to a leading roller for rising twisting machines, especially two-for-one twisting machines. Leading rollers for rising twisting machines, especially two-for-one twisting machines with rotating thread delivery groove receiving the thread, which rollers with heretofore known machines precede the traversing thread guide winder and which rotate with the running ahead shaft, serve for withdrawing the thread from the twisting part. Such leading rollers also serve, as the case may be, with adjustable lead for feeding the thread to the winder or bobbin, while the bobbin sleeve may be driven for instance by a friction roller. Prior to passing over the leading roller, the thread passes through a thread guiding member which may be designed as a so-called pigtail guide. Thereupon the thread passes through the traversing thread guide by means of which the thread during the winding up operation is uniformly distributed over the length of the bobbin sleeve.

Heretofore known leading rollers are provided with a rotating radial thread delivery groove the bottom of which is formed by ball bodies which are alternately offset in axial direction with regard to each other and are partially located in the their respective one or other groove wall. Due to the olfsetting of the balls over the circumference of the thread delivery groove, the groove bottom is correspondingly profiled, and the thread enters into the space between the balls and is thus deviated in its direction a plurality of times. This in turn brings about that the thread will be advanced by the leading roller. However, the numerous deviations of the thread in the groove bottom may damage the thread and also impede the equalization of the thread tension when the thread while sweeping over a triangular surface is being wound upon the bobbin sleeve. The tip of the triangle is in this instance located in the thread delivery groove of the leading roller.

The above-mentioned drawbacks are due to the fact that the numerous thread deviations while assuring a feeding of the thread through the leading roller make it impossible properly to influence the thread tension. To control the thread tension, it is necessary that the thread during its advance by the leading roller may also slip through the groove, in other words may be able to execute a relative displacement with regard to the rotary movement of the thread guiding roller. This, however, is possible only under certain conditions because the thread rests in the groove over a length corresponding to the looping angle and in said groove is correspondingly frequently deviated and grasped by the balls.

It is, therefore, an object of the present invention to provide an arrangement which will overcome the abovementioned drawbacks.

It is another object of this invention to provide a leading roller arrangement which will equalize the tension of the thread passed over such roller.

It is a further object of this invention to provide a leading roller as set forth in the preceding paragraph which will simultaneously assure an improvement in the feeding of the thread through the leading roller.

These and other objects and advantages of the invention will appear more clearly from the following specifi- Claims ice cation in connection with the accompanying drawings, in which:

FIG. 1 represents a section through a leading roller with clamping pins adapted magnetically to be displaced in axial direction of the roller, said section being taken along the line II of FIG. 2.

FIG. 2 is a section taken along the line IIII of FIG. 1.

FIG. 3 illustrates a magnet for use in the roller arrangement of FIGS. 1 and 2.

FIG. 4 represents a section through a modified leading roller with a thread delivery groove formed by ribs and clamping levers.

FIG. 5 illustrates in top view the cooperation of two ribs and a clamping lever according to FIG. 4, said clampin g lever being movable between two ribs.

FIG. 6 is a top view of a rib and clamping lever of an arrangement in which the rib and the clamping surface of the clamping lever are located in one axial plane.

FIG. 7 is a section through a modified leading roller in which one rolling body is provided with radial ribs while the other rolling body is provided with associate ribs which are arranged on pins adapted to be axially displaced by magnetic force, said last mentioned ribs together with the ribs on the other rolling body forming the thread delivery groove.

FIG. 8 is a section through still another modification of a leading roller.

FIG. 9 represents in section a leading roller in which one roller body comprises a non-magnetic disc, whereas the other roller body is provided with pins adapted to be displaced in axial direction by magnetic force.

FIG. 10 is still another embodiment of the invention similar to that of FIG. 9 in which the axially displaceable pins have been replaced by axially displaceable balls.

FIG. 11 is a section through a leading roller in which one of the roller bodies is adapted to be pressed mechanically against the other rolling body in order to reduce the width of the thread delivery groove.

FIG. 12 is a partial section through the hub of a roller body according to FIG. 11.

FIG. 13 shows the mounting of the pressure roller shown in top view in FIG. 11.

FIG. 14 illustrates in section a leading roller comprising two pot-shaped bodies which are adapted by magnetic force to be moved toward each other for reducing the width of the thread delivery groove.

FIG. 15 is a section through a leading roller in which the walls of the thread delivery groove are pressed against each other by spring force and are pressed away from each other by a spreading or spacer roller.

FIG. 16 is a section through a leading roller similar to that of FIG. 15 in which the clamping pressure is adjustable pneumatically.

FIG. 17 illustrates a section through a leading roller with cam for controlling the width of the groove between the two roller bodies.

FIG. 18 is a section through a leading roller similar to that of FIG. 1 with a mechanical control for the clamping pins forming a wall of the delivery groove.

A leading roller according to the present invention is characterized primarily in that at least one of the groove walls is formed by axially displaceable means the movement of which is automatically controlled in such a way that said one groove wall will always in the range between the entry and delivery point of the thread move gradually toward the opposite groove wall and subsequently will move gradually away therefrom. In this way it will be assured that the thread coming from the thread guiding element first enters the thread delivery groove and then while passing through said groove will be briefly clamped in the latter so as to be advanced by the rotating roller and will subsequently be released again from the clamping means and will leave the leading roller on its way to the traversing thread guide. Actually the thread is always clamped in, however, only at points. The explanation given above refers to a passing thread point, i.e. a very short section of the thread which is followed by the subsequent thread section. Inasmuch as the thread is clamped in the leading roller for a very short time only, a uniform advance of the thread will be assured. At the same time the thread is also given the possibility of being able to slip to a certain extent, in other words due to the continuous local displacement of the clamping points, will be able to undergo certain reductions and extensions in its length between the two thread guiding eyes between which the leading roller is located.

According to a further development of the present invention, the movement of the clamping bodies is controlled by at least one magnet which is arranged within the range between the entry and exit points of the thread, said magnet being adapted to press the clamping bodies against the oppositely located groove walls. The provision of a magnet will assure a uniform compression of the two clamping bodies in the range between the entry and exit points of the thread, the strength of said magnet controlling the clamping pressure. The magnets used in connection with the present invention may be permanent magnets or electromagnets. -If electromagnets are employed, the clamping pressure may be varied without having to change the magnets and may be adjusted in conformity with the quality of the thread. In this connection there exists the possibility of controlling the magnets of a plurality of leading rollers at the same time and together in conformity with the strength of the magnets.

In order to assure that the thread when passing over the roller will first be pressed at a very slight pressure which then will gradually increase and subsequently will gradually decrease, the magnets may be so designed that their repelling force will increase from the thread entry point to the thread exit point and then will decrease again.

Various possibilities of arranging the magnets are avail able. According to one possibility magnetic pins may be axially displaceably arranged in one groove wall while being distributed over the circumference of the roller. Within the range of the grooves and between the entry and exit points of the thread there may be stationarily arranged a magnet adapted to repel said magnetic pins so as to press the same against the opposite groove wall. Such an arrangement brings about that one groove wall is formed by the end faces of the magnetic pins so that this groove wall in the form of the end faces of the magnetic pins is moved into clamping position between the thread entry and thread exit points. The magnets may again be so designed that, when the individual magnetic pins pass by said magnets the repellent force will gradually increase and then again gradually decrease.

More specifically, the magnet may be connected to the machine frame and may have its repelling pole face the outer end face of that roller section which comprises the magnetic pins. Thus, both roller sections are rotated together and when passing by the stationary arranged magnet, the magnetic pins are axially displaced in one or the other direction.

Referring now specifically to the embodiment of FIGS. 1 to 3, it will be noted that a shaft 1 carries the two roller sections 2 and 3 of the leading roller generally designated L. Distributed over those end faces of the roller sections 2 and 3 which face each other are axially extending pins 4 which form the bottom of the thread delivery groove 5. When a thread T rests in thread delivery groove 5, it rests radially inwardly on the adjacent surface portion of pins 4. Thread T thus is looped around the groove bottom within the range of its looping angle from pin to pin so that the thread on said pins defines a portion of a polygon. Between pins 4 in roller body 2 there are fixedly inserted clamping members 6 which face recesses 7 in roller body 3. In the particular example shown in FIGS. 1 and 2, recesses 7 have a squareshaped cross section. However, it is to be understood that the said recesses 7 may also have any other cross section. Axially diplaceably mounted in recesses 7 are magnetic pins 8 of a corresponding cross section. According to the specific embodiment shown in FIGS. 1 and 2, the south poles of magnetic pins 8 face the clamping members 6, whereas the north poles of said pins 8 face the porth poles of a magnet 9 the south pole of which is fixedly connected to a supporting member 10 which in its turn is connected to the machine frame 11 in any convenient manner. Magnet 9 extends between the thread entry point and the thread exit point while being slightly spaced from the outer surface of roller body 3. As will be seen from FIG. 2, magnet 9 has a segmental shape which corresponds in its curvature to that of roller body 3. A top view of magnet 9 is shown in FIG. 3.

As will be evident from FIGS. 1 and 3, magnet 9 tapers toward the ends so that its magnetic force will decrease at the ends with regard to the magnetic force at the central section. This will bring about that when roller 2, 3 during its rotation moves by the tationary magnet 9, the magnetic pins 8 will gradually and only at slight pressure he moved against the clamping members 6 in roller body 2, while in the central section of magnet 9 the full magnetic force becomes effective, which will subsequently decrease again. In this way only within the central area a strong clamping effect will occur, whereas the areas with less clamping effect will permit the thread to lide to a certain extent.

As the thread passes through thread delivery groove 5 and is transported further by leading roller 2, 3, the thread has its respective section which is in the groove clamped in the leading roller. Thus, the thread concurrently passes a clamping-advancing area. In contrast to heretofore known leading rollers, only a local clamping effect is exerted upon the thread so that an automatic adaptation to the thread tension behind the leading roller will be obtained. On the other hand, however, the clamping effected by the leading roller is more intensive than is the case with heretofore known leading rollers so that the present invention brings about an important improvement in the feeding of the thread.

According to another embodiment of the present invention that end face of the roller which is adjacent the thread groove may be provided with axially protruding ribs forming one groove wall, while the roller is furthermore provided with angle-shaped clamping levers located between the ribs. These clamping levers are so arranged that one leg forms the bottom of the groove, wherea the other leg forms the other groove wall and is tiltable between the axially extending clamping ribs. To this end, the back side of the lever is provided with a magnet which during the rotation of the leading roller will in the groove range between thread entry and thread exit point pass by a stationary magnet exerting a repelling force upon the magnet of the respective lever.

Thus, such an embodiment represents an arrangement according to the invention in which the thread delivery groove is not formed by rotating groove walls. Instead the thread delivery groove is formed on one hand by protruding rib and on the other hand by clamping levers adapted to move between said ribs so that the thread is slightly deviated a plurality of times between the ribs and the clamping levers and is taken along by the roller while said thread prior to being engaged by said ribs and clamping levers rests on the other lever arm of said tilting lever. The deviation over the looping angle is only slight and is only omewhat stronger at the clamping point proper. This, however, is not harmful and aids in the feeding of the thread by the leading roller.

,5 In conformity with a further development of the present invention, the repelling magnet may be connected to a radially directed flange of a roller body which while being rotatable relative to the leading shaft is prevented from rotating with said shaft so that the magnet is not supported by the machine frame but by the leading shaft itself.

More specifically, with regard to FIGS. 4 to 6, the leading roller comprises two roller bodies 12 and 13 arranged on the leading shaft 1. Roller body 12 is keyed to shaft 1 whereas roller body 13 is movable on shaft 1 by means of a sliding bushing 14. However, roller body 13 does not rotate with shaft 1 but is prevented from doing so by an abutment 15 by means of which it engages an abutment 16 mounted on machine frame 11. An axial displacement of roller body 13 toward roller body 12 is prevented by the slotted hub 17 of roller body 12, whereas a clamping ring 18 on shaft 1 prevents roller body 13 from axially moving in the opposite direction.

As will be seen from FIG. 4, a plurality of two-arm tilting levers 19 uniformly distributed over hub 17 are journalled in said slotted hub 17. Tilting arm 20 of each tilting lever 19 forms a portion of the groove bottom of the thread delivery groove 5, whereas tilting arm 21 forms a groove wall. The other groove wall is formed by ribs 22 which are arranged at that side of roller body 12 which faces roller 13. Normally lever 19 will due to the action of the centrifugal force occupy that position which is shown in the lower part of FIG. 4. In this position, the thread delivery groove is open so that the thread can freely enter the groove and can rest on lever arm 20 in radially inward direction.

The back sides of lever arms 21 carry magnetic bodies 23 having associated therewith a magnet 24 which extends over the range from thread entry to thread exit point. Magnet 24 is connected to roller body 13 which during the rotation of roller body 12 is at a standstill. When roller body 12 rotates and as a result thereof individual tilting levers 19 come into the range of magnet 24, the latter exerts a repelling force upon the respective adjacent magnetic body 23 inasmuch as thus those poles of magnetic bodies 23 and magnet 24 which face each other are of the same nature. Consequently, magnet 24 repels magnet body 23 and thereby causes lever 19 to tilt into that position which is shown in the upper portion of FIG. 4. In this position of lever 19, the thread which occupies the respective thread delivery groove 5 will be clamped.

FIG. 5 shows ribs 22 in such an arrangement that lever arm 21 with magnetic body 23 is located between two ribs 22. Thus, in clamping position, tilting lever 21 extends between two ribs 22 whereby the thread 25 passing through will be slightly deviated and subjected to a clamping action which in turn brings about the feeding or advancing of the thread. FIG. 6 shows a modification of the arrangement of ribs 22 and tilting lever 21. More specifically, one rib 22" axially faces a lever arm 21' so that thread 25 will be located directly between the end faces of a rib 22" and a tilting lever 21'. In this instance the thread is not deviated but is clamped directly between the end faces. The shape of magnet 24 may be the same as shown in FIGS. 1 to 3 and described in connection therewith.

According to a further embodiment of the present invention, axially and radially directed ribs may be provided at both sides of the groove in the leading roller. Those clamping ribs which are located on one side of the groove are fixedly connected to the leading roller, whereas those ribs located on the other side are axially displaceable in the leading roller and with axially directed pushrods extend transverse through the leading roller. The last mentioned ribs are within the range between thread entry and thread exit point located opposite a stationarily arranged magnet adapted to displace the axially displaceable rib bodies toward or between the ribs which are axially connected to the leading roller. With this embodi- 6 merit of the invention, the thread advance is similar to that described above, but the arrangement differs therefrom in that the ribs forming the groove wall move relative toward each other in a precisely axial direction, said movement not being due to .a tilting movement.

More specifically, with regard to FIG. 7, the leading roller is again composed of two roller bodies 26 and 27 which are fixedly connected to leading shaft 1. That side of roller body 26 which faces the groove 5 is provided with ribs 28 which face ribs 29 axially located opposite ribs 28 or somewhat offset with regard thereto so that the thread delivery groove 5 is located between ribs 28 and 29. The free ends of ribs 28 and 29 are angled toward the outside so that groove 5 flares toward the outside. Ribs 29 are formed onto axially displaceable pushrods 30 or they are connected thereto. The axially displaceable pushrods 30 pass through the two roller bodies 26 and 27 and extend through axial recesses 31 therein. The displacement of pushrods 30 is limited by the length of recesses 32 respectively associated with each rib 29 of roller body 27. That free end of each pushrod 30 which passes through roller body 26 carries a magnetic plate 33 which, if desired, may also form a soft iron plate. Plates 33 of pins or pushrods 30 have associated therewith a magnet 34 which is fixedly connected to machine frame 11 and has a segmental shape similar to that shown in FIG. 1. This magnet extends over a portion of .a circle only and may have the same cross section as magnet 9 in FIGS. 1 to 3. Due to this cross section there will likewise be obtained an increase and decrease of the magnetic force exerted upon plates 33 while they pass magnet 34. Magnet 34 extends over the range between the thread entry and thread exit point of the leading roller when the latter rotates. The cooperation of ribs 28 and 29 may be similar to that described in connection with FIGS. 4 to 6. The groove bottom is formed by pushrods 30 which have a function similar to that of tilting arms 20 of FIG. 4. Accordingly, also the operation of the leading roller of FIG. 6 corresponds to that described in connection with FIG. 4.

It is also possible to realize the present invention by designing the leading roller as a roller body rotating with the leading shaft and by providing said roller body with axially extending pins distributed over the circumference of said roller body. In such an instance, the said pins are respectively provided with axially displaceable magnets which are adapted to be pressed against the end face of the roller body for purposes or clamping the thread. The end face of said roller body is located opposite to a roller body rotatable on said leading shaft. The roller body within the range between thread entry and thread exit point carries a magnet repelling the magnetic body, whereas in the remaining range, magnets are provided adapted to attract the magnetic body. Whereas With the above mentioned embodiments the spacing of one groove wall from the other groove wall is effected by the thread entering the groove if such spacing does not automatically occur during the rotation of the roller, with the last mentioned embodiment of the present invention, an automatic control of one groove wall will be assured. To this end, the magnets forming one axially displaceable groove wall are automatically pressed against the other groove wall when said magnets come into the range between thread entry and thread exit point, and are again withdrawn from the groove wall when said magnets leave said range. The withdrawal of said magnets is effected by special magnets. Corresponding withdrawal magnets may, of course, also be provided with the .above mentioned embodiments.

Referring more specifically to FIG. 8, the leading roller comprises roller bodies 35 and 36. Roller body 35 is normally held stationary on shaft 1, whereas roller body 36 is rotatably journalled on shaft 1 through the intervention of a bushing 37. An axial displacement of roller 35, 36 in one direction is prevented by a clamping ring 18. Roller body 35 is mounted on shaft 1 by means of a radially directed pin 38 which is under the thrust of a spring 39 so that as the case may be a relative rotation of roller body 35 with regard to shaft 1 would be possible.

Pins 40 extend in axial direction through roller body 35, said pins being uniformly distributed and being respectively provided with head plates 41. Each of said pins 40 has placed thereon axially displaceable magnetic discs 42 which have respectively associated therewith magnetic bodies 43 connected to roller body 36. Roller body 36 is by an abutment 15 prevented from rotating, said abutment being connected to frame 11. Magnetic discs 42 which form the groove wall of roller body 36 in thread delivery groove have oppositely located thereto the groove wall of roller body 35 which within the range of each magnetic disc 42 is provided with metallic sheathing 44. Magnetic body 43 which, due to the stationary support of roller body 36 is located within the range between thread entry and thread exit point, has its south pole facing the roller body 35. Thus, magnetic body 43 exerts a repelling force upon magnetic disc 42 and presses the same against roller body 35 so that a thread therebetween will be clamped. In this connection, magnetic disc 42 will be displaced on its pin 40. When a magnetic disc 42 during rotation of roller body 35 leaves the range of magnetic body 43 located between thread entry and thread exit point, magnetic disc 42 will move into the range of other magnetic bodies 43' which have the reverse arrangement of the poles. This is shown in the lower section of FIG. 8. In this instance, the north pole of the respective magnetic body 43 attracts the respective magnetic disc 42 so that thread delivery groove 5 will be widened and the thread will be free so that it can easily leave thread delivery groove 5 and pass to the thread guiding eye.

According to a further modification of the present invention, the leading roller may consist of a roller body which rotates together with the leading shaft and which is provided with uniformly distributed axially displaceable clamping pins which on the groove side are movable out of the roller body so as to engage a disc connected to the roller body, said disc together with the end face of the roller body forming the groove. Within the range between thread entry and thread exit point behind the disc there is stationarily arranged a magnet, whereas in the remaining range on the other side of the roller body there is provided a further magnet exerting an attractive force. Also this arrangement Works similar to the above outlined embodiments of the invention and is characterized primarily in that one groove wall is formed merely by a disc rotating with the roller body. This will greatly reduce the weight and will make the production of the roller body particularly simple.

More specifically referring to FIG. 9, it will be seen that this arrangement has a single massive roller body 45 only which is connected to a leading shaft 1. On the side of the thread delivery groove 5, roller body 45 has mounted thereon a disc 46 of non-magnetic material. The outer rim portion is bent toward the outside so that the curvature of the outer marginal portion is about an image to the curvature of that outer marginal portion of roller body 45 which is adjacent the groove. In this way, an outwardly flaring thread delivery groove is obtained, the bottom of which is formed by axially extending pins 47 which extend through roller body 45 and disc 46. Between pins 47 there are respectively arranged recesses 48 in roller body 45. The cross section of said recesses 48 may correspond to the cross section of the recesses 7 according to FIG. 1. Axially displaceably mounted in recesses 48 are magnetic bodies 49 of corresponding cross section the north pole of which is directed toward disc 46. In the range between the thread entry and thread exit points and stationarily the outside of disc 46 there is provided a magnet 50 which is connected to frame 11 by means of an angle 10. The shape of magnet 50 may correspond to the shape of the magnet 9 of FIG. 3. In the remaining sections or in one portion on the outside of roller body 45 there are provided one or more magnets 57 which are stationarily arranged and the north pole of which faces roller body 45. Thus, magnet 50 will be able to displace magnetic pins 49 between the entry and the exit points of the thread against disc 46 so that the thread is clamped between disc 46 and end faces of magnetic pins 49. On the other hand, in the remaining ranges, magnetic pins 49 are removed from disc 46 by magnets 57. In the last mentioned ranges, therefore, a clamping of the thread cannot occur. In other words, the thread clamping operation is exclusively limited to the range covering the area from the thread entry to the thread exit points.

According to a further embodiment of the present invention, the leading roller comprises a roller body which rotates with the leading shaft. The roller body at the side of the groove carries a disc which, together with the associated end face of the roller body, forms the groove. At the level of the groove bottom, the roller body has bores which are distributed over the circumference and each of which has a ball therein. Each ball is within the range between thread entry and thread exit point displaced toward the disc by means of a magnet and engages in one of the grooves arranged along a circle in the disc. In the remaining range, each ball is moved away from the disc by a magnet which is stationarily arranged. This roller body differs from the roller bodies described above in that one groove wall is formed by balls so that the thread when passing through the groove over the ball surfaces will undergo a certain arch-shaped deviation whereby the adherence and clamping of the thread will be improved. In addition thereto, the balls will assure a uniform and precise axial displacement without the danger of clamping or jamming in its guiding means, which clamping and jamming may occur with axially displaceable pins if manufacturing tolerances have not been maintained.

Referring more specifically to FIG. 10, the arrangement shown therein is somewhat similar to that of FIG. 9. As will be seen from FIG. 10, leading shaft 1 has mounted thereon a roller body 51 with axially directed pockets 52 adjacent the groove side, each of said pockets receiving a ball 53. Pockets 52 and balls 53 have associated therewith ball-cup-shaped recesses 54 provided in disc 55. The outer marginal portion of disc 55 and the outer marginal portion of roller body 51 adjacent the groove corresponds in shape to the marginal portions of these elements in FIG. 9. Between the entry and the exit points of the thread, on the outside of disc 55 there is located a magnet 57' which by means of an angular member 10 is connected to the machine frame 11. This magnet operates in such a way that the respective ball 53 passing by magnet 57 is pulled into the semi-spherical-shaped sockets 54 of disc 55. The respective thread section within this area is clamped between the inner surface of socket 54 and the outer surface of ball 53. Outside the range between thread entry and thread exit points, balls 53 are pulled into the interior of pockets 52 by means of magnets 57:: which are stationarily connected to machine frame 11, in other words, do not rotate with the roller body 51.

As will be evident from FIG. 10, the thread delivery groove 5 will by balls 53 be narrowed within the range between thread entry and thread exit points up to a clamping of the thread, whereas the delivery groove in the remaining range is open to the groove bottom while said groove bottom is formed by the inner marginal portion of the semi-spherical socket 54.

According to the arrangement of FIG. 11, leading shaft 1 has mounted thereon a roller body 58 with an axially directed hub 59 which latter at the outside thereof is provided with teeth 60. Placed upon hub 59 is a potshaped disc 61 adapted to be rotated by hub 59 through the intervention of teeth 60 which mesh with corresponding teeth of pot-shaped disc 61. The intermeshing of the teeth 60 with the teeth of disc 61 is effected with play (FIG. 12) so that disc 61 will be able to carry out wobbling movements as will be evident from FIG. 11. Disc 61 has its clamping surface 62 pressed against groove Wall 63 of roller body 58 within the range from the thread entry to the thread exit points. This pressing is effected mechanically by means of a pressure roller 64 which resiliently engages the pot-shaped disc 61. Pressure roller 64 is journalled on a stud 65 which in its turn is supported by a spring 66 connected to machine frame 11 by an angle piece at 67. The resilient sup port for disc 61 is more clearly shown in FIG. 13.

According to a further embodiment of a leading roller according to the present invention, the leading roller may be composed of a non-magnetic roller body rotating with the leading shaft. The non-magnetic roller body is provided with a hub equipped with teeth on which hub there is axially displaceably arranged a non-magnetic disc body which rotates with the roller body. The said disc body carries magnets or soft iron pieces at that side which is adjacent the roller body. By means of said magnets or soft iron pieces, the disc is within the range from thread entry to the thread exit point pressed against the end face of the roller body by a stationarily arranged magnet. The arrangement of one disc on a toothed wheel hub converts the disc so to speak to a swash plate adapted to carry out wobbling movements. These wobbling movements are controlled by the magnets in such a way that within the range between the thread entry and the thread exit points the said swash plate will approach the other disc so that the thread will be clamped therebetween within this range only. For all practical purposes, the two discs engage each other only along a radical line so that the thread is clamped only locally. The thread will therefore be positively fed but will be able in case of differences in the tension to slip between the discs when the clamping pressure is adjusted accordingly.

The arrangement illustrated in FIG. 14 comprises a leading roller which is composed of two pot-shaped discs 68 and 69 of which disc 68 is connected to shaft 1 by means of hub 70. Hub 70 has its outer periphery provided with teeth 60 meshing with corresponding teeth of disc 69. The teeth of the two discs mesh with each other with play in the manner shown in FIG. 12 so that disc 69 similar to disc 61 of FIG. 11 will be able to carry out .wobbling movements. The back side of disc 69 is equipped with an annular body 71 of soft iron.

As will be seen from FIG. 14, the disc bodies 60 and 69 forming the leading roller rotate together while that section of disc 69 which is pressed against disc 68 passes into the range between the thread entry and thread exit points, in other words into the range in which magnet 72 is located which latter by means of an angle, member 10 is connected to the machine frame 11. The groove bottom i formed by the head portion of teeth 60 of hub 70 as is also the case with the embodiment of FIG. 11.

Instead of actuating the clamping bodies by means of magnets, it is also possible according to the present invention to control the movement of the clamping bodies by mechanically operable cam means arranged in the range between the thread entry and thread exit points. Furthermore, the leading roller may be composed of two mutually engaging roller bodies which are firmly connected to the leading shaft, while the gap broadens radially outwardly into a groove. In the bottom of the groove transverse to the two roller bodies there are uniformly distributed over the circumference of the roller bodies transverse pins which form the bottom of the groove on which the thread can radially rest when passing through the roller.

More specifically, the leading roller may be composed of a roller body rotating together with the leading shaft.

The roller body is provided with an axially extending toothed hub forming the bottom of the groove, and an axially displaceable annular disc may be mounted on the hub, said disc rotating together with the roller body while in the range between the thread entry and thread exit points a pressure roller is adapted to engage the disc from the outside. Said pressure roller will in the mentioned range narrow the groove between roller body and disc. Also in this instance, one disc forms a kind of swash plate which automatically through the intervention of the pressure roller will, within the range between the thread entry and thread exit points, engage the end face of the roller. As a result thereof, the thread delivery groove will continuously be narrowed and widened while the narrowing up to the clamping action will be effected solely within the range between the thread entry and thread exit points.

According to another embodiment of the invention, the leading roller is composed of two roller bodies fixedly arranged on the leading shaft in spaced relationship to each other. These roller bodies have those sides which face each other provided with profiled discs which are pressed against each other by spring means interposed between the roller bodies and the discs. A spreading or spacer member extends between the discs in such a way that the clamping discs will engage each other solely within the range between the thread entry and thread exit points. With such a leading roller, provision is made that the discs which form the groove walls will always engage each other under clamping pressure. Due to the fact that the spacer member extends therebetween, the said discs will be lifted from each other while the engagement between said discs will be retained only over a certain local range.

Referring now to FIG. 15, this figure shows a leading roller composed of two roller bodies 73 and 74 connected to leading shaft 1. Roller bodies 73 and 74 are provided with recesses at those sides which face each other. Roller bodies 73 and 74 have inserted therein discs 75 and 76 in loose engagement with each other. Discs 75 and 76 are provided with semispherical depressions 77 which are so arranged that the depressions 77 of one disc extend between the depressions of the other disc. The two discs 75 and 76 are pressed against each other by springs 78 and 79. Springs 78 and 79 have their axial outer ends rest on roller bodies 73 and 74 respectively. The engagement of discs 75 and 76 and their depressions 77 is limited to the range between the thread entry and thread exit points. Over the remaining range, discs 75 and 76 are spaced from each other by means of spacer roller 80. According to a further modification of the present invention, the leading roller may be composed of two roller bodies connected to the leading shaft while said roller bodies have those sides thereof which face each other provided with axially elastically deformable annular bodies. Those walls of said annular bodies which face each other consist of wear resistant and torsion resistant material, as for instance steel sheet.

A spacer member extends between said walls in such a way that the elastically deformable annular bodies will have their wear resistant wall sections in engagement with each other solely within the range between the thread entry and thread exit points. The spacer member will thus bring about a deformation of the walls in such a way that they will engage each other solely in the above mentioned range within which the thread will be clamped and from where the thread will be conveyed to the traversing thread guide.

A similar leading roller may also consist of two roller bodies connected to the leading shaft while said roller bodies have those end faces thereof which face each other each provided with clamping rings resting on the- 1 1 each other solely within the range between the thread entry and thread exit points. The delivery of the thread and its advance are with this arrangement effected in the same manner as described above.

With this embodiment, the elastic annular cushion may be designed as compressed gas or liquid cushion the pressure of which may be varied thereby permitting a variation in the clamping pressure. To this end, according to a further development of the invention, the annular cushion may be connected to the leading shaft which may be designed as supply pipe for the pressure medium. Thus, the pressure cushions of all leading rollers may simultaneously be supplied with a pressure medium while in all pressure cushions simultaneously the pressure and thus the clamping effect may be varied in order to adapt the pressure to the respective thread quality.

Referring more specifically to FIG. 16, the arrangement shown therein illustrates a leading roller composed of two hollow bodies 81 and 82 which are connected to leading shaft 1. Roller bodies 81 and 82 are at that side which is adjacent the thread guiding groove provided with recesses 83 and 84. Recesses 83 and 84 are covered by discs 85 of elastic material, as for instance natural or synthetic rubber, and are closed in an air-tight or fluidtight manner. Leading shaft 1 is hollow and through bores 86, 86 communicates with recesses 83 and 84 so that the inner pressure in the recesses may be varied. A plurality of leading rollers of this type may through hollow shaft 1 be supplied with compressed air, a pressure gas or a pressure fluid. Hollow clamping rings 87 with semispherical depressions 77 rest upon the respective elastic discs 85 similar to the arrangement of FIG. 15. According to FIG. 16, clamping rings 87 are composed of two sections while at least those portions which form the Walls of delivery groove consist of non-elastic material. Clamping rings 87 will within the range between the thread entry and thread exit points engage each other while exerting a clamping effect, whereas over the remaining section they are spaced from each other by spacer roller 80.

According to a further modification of the present invention, the leading roller may consist of a roller body rotating with the leading shaft. The said roller body has on that side thereof which is adjacent the groove axially displaceable pins with heads. These pins which are uniformly distributed over the circumference of the roller body extend through a hood-shaped roller body while between the pin heads and the hood body springs are slipped on the pins, and the heads of the pins engage a cam member which is so designed that the roller body and the hood-shaped roller body will engage each other solely within the range between the thread entry and the thread exit points. The leading shaft may be rotatable relative to the cam body which is stationarily arranged with regard to the shaft. Thus, the cam body is supported by the leading shaft without, however, rotating with said shaft.

Referring now to FIG. 17, the leading roller shown therein comprises a roller body 88 which is fixedly arranged on shaft 1. The arrangement of FIG. 17 furthermore comprises a pot-shaped disc 89 adapted to carry out wobbling movements and held on said roller body 88 by means of pins 90. Springs 92 are arranged between heads 91 of pins 90 and pot-shaped disc 89. Pins 90 engage recesses 93 in roller body 88 and are free to tilt. Heads 91 of pins 90 rest on a cam 94 which by means of sliding bushing 95 is rotatable relative to shaft 1 and is secured against axial displacement in one direction by a clamping ring 96. Cam disc 94 is prevented from rotation by engagement of abutment 15 with a counter abutment 16 which is connected to machine frame 11. Guiding surface 97 on cam disc 94 is so shaped that pot-shaped disc 89 will be pressed against roller body 88 within that range which during rotation of the leading roller is located between the thread entry and the thread exit points.

The groove bottom is formed by pins 92. The axial displacement of pot-shaped disc 89 by cam surface 97 and through the intervention of springs 92 is so effected that the pot-shaped disc 89 carries out a wobbling movement while within the range between the thread entry and thread exit points the thread is clamped between disc 89 and roller body 88.

According to a further variation of the present invention, the leading roller may be composed of two roller bodies which are fixedly connected to shaft 1 and engage each other. One of said roller bodies is provided with axially displaceable clamping sleeves distributed over the circumference of said roller body. The ends of clamping sleeves protrude from the roller body and due to the thrust of a spring engage a cam body which displaces the pins toward the other roller body within the range between the thread entry and the thread exit points. Similar to the above outlined arrangements, one groove wall is formed by end faces of pins which by means of cams are pressed against the thrust of springs against the other groove wall. This pressing action by the cam section is effected merely within the range between the thread entry and the thread exit points in order within this range to clamp the thread and to advance the same. Over the remaining section, the clamping pins are displaced outwardly by the spring force.

Finally, with regard to FIG. 18, this figure shows an arrangement according to which two roller bodies 98 and 99 are fixedly connected to shaft 1. The design of roller bodies 98 and 99 is similar to that of the roller bodies disclosed in FIG. 1. Roller body 98 is provided with clamping members 6. Axially extending pins 4 engage roller bodies 98 and 99 and form the bottom of the groove. The groove wall of roller body 98 is formed by clamping members 6, whereas groove wall of roller body 99 is formed by clamping pins 100 which are uniformly distributed over the circumference of roller body 99. Clamping pins 100 are arranged in the axially extending recesses 101 of roller body 99. Mounted on the outer end face is a closure disc 102 against which each pin 100 may rest by means of a collar 103. A spring 104 acts from the other side against collar 103, said spring 104 resting on a shoulder 105. In view of the action of spring 104, pins 100 have the tendency to move away from thread delivery groove 5. In the range between the thread entry and the thread exit point, pins 100 are displaced toward clamping members 6 or roller bodies 98. In addition thereto, the ends 106 of the individual pins 100 will within the range between the thread entry and the thread exit points engage cam disc 107 which is connected to machine frame 11 through the intervention of an angle member 10. Cam 107 is so shaped that pins 100 will be gradually moved into clamping position and will also gradually be moved away from and out of clamping position. In the thread delivery groove 5 the thread will rest on the bottom of the groove formed by transverse pins 4. When passing over the leading roller, the thread will within the range between the thread entry and thread exit points he held between clamping members 6 and the end faces of pins 100 and in this way will be advanced.

All the above described leading rollers have in common that when the thread passes over the leading roller it will be clamped locally only and will be advanced while the clamping point does not shift in the leading roller. However, the clamping stations of the thread will change continuously with the movement of the thread over the leading roller. This brings about that the thread undergoes a certain equalization of tension while it is grasped only over a very short range and over the remainder of the range, is freely movable in the leading roller. This permits an adaptation of the thread to the reciprocatory movement of the traversing thread guide eye while resulting in an equalization of the thread tension. The thread is clamped by axial forces. A devia- 13 tion of the thread within the thread delivery groove will occur with a few of the above examples only and to a minor extent so that as the case may be a sliding of the thread is possible when this is required in order to aid in the uniform tensioning of the thread, in other words when excessive thread tensions occur.

As far as those examples are concerned in which the clamping pressure is produced by magnetic forces, it will sufiice when the magnetic body at one side of the delivery groove is in the form of a permanent or an electromagnet, whereas the other magnetic body preferably may consist of soft iron bodies. If electromagnets are provided, the magnetic force may be varied. This furnishes the possibility of adjusting and varying together the clamping pressure of a group or of all leading rollers of the machine.

It is, of course, to be understood that the present invention is, by no means, limited to the particular arrangements shown in the drawings but also comprises any modifications within the scope of the appended claims.

What I claim is:

1. A leading roller arrangement for textile machines, especially two-for-one twisting machines, which includes: a roller with a thread receiving and delivery groove, clamping means forming a portion of said groove and being reciprocable in axial direction of said roller, said clamping means include magnetically responsive means circularly distributed in said roller, and control means operable automatically within the range from a point where a thread enters said groove to a point where said thread leaves said groove to impart upon said clamping means an axial movement in a groove narrowing direction, said control means including a magnet arranged within the range from said thread entry point to said thread exit point and operable magnetically to affect said magnetically responsive means to thereby exert an axial movement upon the same in a groove narrowing direction.

2. A leading roller arrangement according to claim 1, which includes additional magnets arranged outside said range from the thread entry point to the thread exit point of the groove and operable to impart upon said magnetically responsive means a movement in axial direction of said roller in a groove widening sense.

3. An arrangement according to claim 1, in which said magnet is so shaped as to have its greatest magnetic force in the central area thereof while said magnetic force gradually decreases to the end portions of said magnet.

4. A leading roller arrangement for textile machines, especially two-for-one twisting machines, which includes: a roller having a circumferential groove, a plurality of magnetic pins substantially uniformly distributed in one side wall of said groove and being displaceable in axial direction of said roller, said groove being adapted at one point of the rotative path of said roller to receive a thread and at another point of the rotative path of said roller to discharge a thread, and a magnet arranged stationarily within the area between said two points and operable to impart upon the respective magnetic pins Within said area a repelling magnetic force to move the respective magnetic pins in a groove-narrowing direction so as to clamp an adjacent thread portion in said groove. 5. A leading roller arrangement according to claim 4, which includes stationary frame means having said magnet connected thereto, those ends of said magnet and said magnetic pins which faceeach other having the same polarity.

6. A leading roller arrangement for textile machines, especially two-for-one twisting machines, which includes: a roller body having one end. face thereof provided with radially extending rib means, said rib means being substantially uniformly distributed over said one end face, a plurality of lever means respectively associated with said rib means and tiltably connected to said roller body, each of said lever means having a first arm and a second arm at an angle to said first arm, said first arm together with said second arm and the respective adjacent rib means confining a groove, said first arm being movable from a first position in which the respective groove has its greatest width to a clamping position in which a thread received in the respective groove is clamped therein, said first arm including magnetically responsive means, and a magnet arranged within the range between a point of the circular path of said roller where a thread enters a groove and the point where the thread in said last-mentioned groove leaves the same, said magnet being operable to exert upon the respective adjacent lever means a tilting action to pivot the respective adjacent lever means to its clamping position.

7. An arrangement according to claim 6 which includes a shaft having said roller body connected thereto for rotation therewith, and also includes supporting means supported by said shaft while permitting said shaft to rotate relative to said supporting means, said supporting means supporting said magnet.

8. A leading roller arrangement for textile machines, especially two-for one twisting machines, which includes: a roller having a first roller body and a second roller body in axial alignment with each other, those end faces of said first and second roller bodies which face each other being provided with a first and a second set respectively of radially extending rib means substantially uniformly distributed over said respective end faces, a plurality of pin means reciprocable in said roller in axial direction thereof and having an end protruding from said roller, the rib means of said second set of rib means respectively being connected to said pin means for reciprocation therewith, said pin means and the respective adjacent rib means of said first and second sets confining groove means for receiving a thread at the start of a certain rotary path section of said roller and releasing said thread at the end of said path section, said protruding end of said pin means being magnetically responsive, and stationary magnetic means arranged within the range of said path section and operable magnetically to act and impart upon the respective adjacent pin means an axial movement thereof to move the respective rib means connectedto said lastmentioned pin means in a direction toward the respective adjacent rib means of said first set for clamping a thread received between said last-mentioned two rib means.

9. A leading roller arrangement for textile machines, especially two-for-one twisting machines, which includes: a shaft, a roller supported by said shaft for rotation therewith, a plurality of means spaced from each other and extending through said roller in axial direction of said shaft, a plurality of magnetically responsive means respectively supported by and reciprocable on said pin means, said pin means and said magnetically responsive means together with the respective adjacent end face of said roller confining groove means adapted at the start of a certain section of the rotary path of said roller to receive and at the end of said section to discharge a thread portion, first magnet means adapted to be held stationary and located within the range of said path section for exerting a repelling force on the respective adja cent magnetically responsive means on said pin means, and second magnet means adapted to be held stationary and arranged outside said path section for exerting an attractive force on the respective adjacent magnetically responsive means on said pin means.

10. A leading roller arrangement for textile machines, especially two-for-one twisting machines, which includes: a rotatable roller, a plurality of magnetically responsive clamping pins extending in axial direction of said roller and 'reciprocably arranged therein while being substantially uniformly spaced from each other, said pins having an end portion thereof being movable beyond an end face of said roller, disc means connected to said roller and comprising depressions for receiving said end portions, the outer marginal portions .of said disc means and said roller respectively adjacent said depressions and said pins forming with each other an annular groove of a width considerably wider than the thickness of a thread to be passed through said groove, first stationary magnet means extending near said depressions over a section only of the rotative path of said disc means for pulling the respective adjacent end portions of said .pins into the respective adjacent depressions within the range of said section, and second stationary magnet means arranged outside said section and adjacent to said roller for pulling the respective adjacent pins out of said depressions.

11. A leading roller arrangement for textile machines, especially two-for-one twisting machines, which includes: a rotatable roller having an end face provided with a plurality of recess means substantially equally spaced from the axis of said roller and from each other, a plurality of balls respectively arranged at least partially in said recess means, disc means connected to said roller and being provided with a plurality of socket-shaped depressions arranged opposite said recess means and adapted partially to receive the balls from the respective adjacent recess means, the outer marginal portions of said disc means and said roller respectively adjacent said depressions and said recess means forming an annular groove of a width considerably greater than the width of a thread to be passed through said groove, first stationary magnet means arranged adjacent at least one of said depressions within the range of a portion of the rotary path of said disc means, and said second stationary magnet means arranged adjacent said roller within the range of said depressions and outside said portions.

12. A leading roller arrangement for textile machines, especially two-for-one twisting machines, which includes: a shaft, a non-magnetic roller body connected to said shaft for rotation therewith, said roller body having a hub portion the periphery of which is provided with teeth, non-magnetic disc means in meshing engagement with said teeth for rotation with said roller body, magnetically responsive means arranged near the periphery of said roller body, said disc means being adapted to perform a wobbling movement so that one marginal portion thereof is movable close to the respective adjacent marginal portion of said roller body for clamping a thread therebetween while the oppositely located marginal portion of said disc means is considerably spaced from the respective adjacent marginal portion of said roller body, and stationarily arranged magnet means operable to pull said disc means close to the respective adjacent marginal portion of said roller body within the range of the rotary path of said roller body where a thread to be passed over said roller body enters and leaves a gap between marginal portions of said roller body and said disc means.

13. A leading roller arrangement for textile machines, especially two-for-one twisting machines, with two rotatable roller bodies interconnected for rotation with each other and arranged in face-to-face relationship while forming therebetween a groove opening radially outwardly for receiving a thread, which includes: pin means forming the bottom of said groove and being supported by one of said roller bodies while having their longitudinal axes extending substantially parallel to and uniformly spaced from the axes of rotation of said roller bodies, said pin means being circularly spaced from each other by substantially equal distances and being reciprocable in a direction parallel to the axes of rotation of said roller bodies from said one roller body to the other roller body and vice versa, and controlling means associated with said one roller body and operable to reciprocate said pin means during rotation of said roller bodies.

14. A leading roller arrangement for textile machines, especially two-for-one twisting machines, which includes: a shaft, a roller comprising a first and a second roller body arranged in spaced relationship with regard to each other and connected to said shaft for rotation therewith, first and second profiled disc means interposed between said first and second roller bodies and adapted to carry out a wobbling action with regard to each other, first spring means arranged between said first roller body and the respective adjacent disc means, second spring means arranged between said second roller body and the respective adjacent disc means, the marginal portions of said disc means forming with each other passage means for receiving a thread, and spacer means extending between said disc means at the peripheral portion thereof for spreading the respective adjacent marginal portions of said disc means from each other while the diametrically oppositely located marginal portions are pressed by the respective adjacent spring means into engagement with each other, said last-mentioned marginal portions forming a certain section of the rotary path of said roller to receive at the start of said section a thread and to release said thread at the end of said section.

15. A leading roller arrangement according to claim 14, in which said spring means are formed by pressure fluid inflatable means.

16. A leading roller arrangement for textile machines, especially two-for-one twisting machines, which includes: a shaft, a roller comprising a first roller body and a second roller body arranged in spaced relationship to each other and fixedly connected to said shaft, two elastically deformable annular bodies respectively mounted on those end faces of said roller bodies which face each other, those wall portions of said annular bodies which face each other being provided with wear resistant and distortion resistant wall portions, said annular bodies engaging each other along adjacent end face portions which are located within a certain section of the rotary path of said annular bodies within which a thread is to be clamped, and spreader means extending between marginal portions of said annular bodies outside said certain section.

17. An arrangement according to claim 16, in which said elastically deformable annular bodies form pressure fluid containing cushions, means associated with said cushions for varying the pressure therein.

18. An arrangement according to claim 16, in which said shaft is hollow for connection with a pressure fluid source and comprises passage means communicating with said annular bodies.

19. A leading roller arrangement for textile machines, especially two-for-one twisting machines, which includes: a shaft, a first roller body connected to said shaft for rotation therewith, a second roller body surrounding said shaft so as to be able to carry out a wobbling action with regard to said first roller body, said first and second roller bodies having a marginal area within a certain section of the rotary path of said roller bodies in close arrangement with regard to each other for receiving and clamping a thread therebetween and having a diametrically opposite marginal area of said roller bodies relatively widely spaced from each other, a plurality of pin means with one end portion thereof always in said first roller body and with the other end portion in said second roller body, cam means operable within said certain section to move said pin means in the direction toward said first roller body, and spring means associated with said pin means and operable in response to said cam means moving the respective pin means in the direction toward said first roller body for moving an area of said second roller body into thread clamping position with regard to the respective adjacent area of said first roller body.

20. An arrangement according to claim 19, in which said cam means is supported by said shaft while permitting rotation of said shaft relative to said cam means.

21. A leading roller arrangement for textile machines, especially two-for-one twisting machines, which includes a rotatable shaft, a roller comprising a first and a second roller body arranged in face-to-face relationship with each other while confining a marginal thread receiving and releasing groove therebetween, said first and second roller bodies being connected to said' shaft for rotation 1 7 therewith, a plurality of clamping members extending substantially parallel to said shaft in substantially uniformly spaced relationship to the axis of said shaft, said clamping members being reciprocable in said second roller body and being adapted to engage the adjacent end face of said first roller body within the range of said groove to clamp a thread therebetween, spring means associated with said clamping members for continuously urging the same out of engagement with said first roller body, and cam means arranged within the range of a certain section of the rotary path of said roller bodies for moving the respective adjacent clamping members into thread clamping engagement with said first roller body.

References Cited UNITED STATES PATENTS 473,254 4/ 1892 Dodge 74-23024 1,054,025 2/1913 Pa'ulsen 74-23024 1,663,689 3/ 1928 Ellis 74-23024 3,034,767 5/ 1962 Gordon. 3,104,792 9/ 1963 Walton 226-183 X 3,193,254 7/1965 Minnick 74-230.24 X

M. HENSON WOOD, 1a., Primary Examiner.

I. N. ERLICH, Assistant Examiner. 

1. A LEADING ROLLER ARRANGEMENT FOR TEXTILE MACHINES, ESPECIALLY TWO-FOR-ONE TWISTING MACHINES, WHICH INCLUDES: A ROLLER WITH A THREAD RECEIVING AND DELIVERY GROOVE, CLAMPING MEANS FORMING A PORTION OF SAID GROOVE AND BEING RECIPROCABLE IN AXIAL DIRECTION OF SAID ROLLER, SAID CLAMPING MEANS INCLUDE MAGNETICALLY RESPONSIVE MEANS CIRCULARLY DISTRIBUTED IN SAID ROLLER, AND CONTROL MEANS OPERABLE AUTOMATICALLY WITHIN THE RANGE FROM A POINT WHERE A THREAD ENTERS SAID GROOVE TO A POINT WHERE SAID THREAD LEAVES SAID GROOVE TO IMPART UPON SAID CLAMPING MEANS AN AXIAL MOVEMENT IN A GROOVE NARROVING DIRECTION, SAID CONTROL MEANS INCLUDING A MAGNET ARRANGED WITHIN THE RANGE FROM SAID THREAD ENTRY POINT TO SAID THREAD EXIT POINT AND OPERABLE MAGNETICALLY TO AFFECT SAID MAGNETICALLY RESPONSIVE MEANS TO THEREBY EXERT AN AXIAL MOVEMENT UPON THE SAME IN A GROOVE NARROWING DIRECTION. 